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Volume 25 (2008)
- Issue 4 Pages 70-
- Issue 3 Pages 37-
- Issue 2 Pages 22-
- Issue 1 Pages 1-
Volume 25, Issue 3
Displaying 1-6 of 6 articles from this issue
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Tetsushi SAITO2008 Volume 25 Issue 3 Pages 37-39
Published: July 01, 2008
Released on J-STAGE: October 03, 2008
JOURNAL FREE ACCESS -
Shoji KIDO, Yuichi OHGA2008 Volume 25 Issue 3 Pages 40-42
Published: July 01, 2008
Released on J-STAGE: October 03, 2008
JOURNAL FREE ACCESSThe subtracted images obtained from double arterial hepatic dynamic CT using multi-detector row CT(MDCT) are useful in detecting hepatic tumors which show subtle enhancement in the second phase. However, manual subtraction of MDCT images is time-consuming for radiologists. So, we have developed a fully automated dynamic subtraction algorithm of hepatic CT by use of 3D phase only correlation method for improvement of detection of hepatic tumors. Our algorithm was as follows. In the first step, global-matching processing was performed based on extracted bone regions. In the next step, local-matching processing was performed for the liver area. In the final step, subtraction processing was performed. We evaluated our algorithm using 12 clinical cases, and obtained promising results.View full abstractDownload PDF (518K) -
Yoshihiro SUGATA, Shoji KIDO, Hayaru SHOUNO2008 Volume 25 Issue 3 Pages 43-47
Published: July 01, 2008
Released on J-STAGE: October 03, 2008
JOURNAL FREE ACCESSFor the diagnosis of diffuse lung diseases on CT images, we have used two-dimensional(2D)images. Now, we can easily obtain minute volume data of human body by use of multi-detector row CT, and can diagnose diffuse lung diseases by use of three-dimensional(3D)images. In this study, we focused attention on the patterns of diffuse lung diseases, and tried the computerized analysis method for the image features of the three-dimensional CT images. And we compared the classification results obtained from 3D feature analysis with those obtained from 2D feature analysis. Image patterns for the computerized analysis are as follows: consolidation, ground-glass opacity, reticular, honeycomb, cyst, nodular and normal. In order to evaluate these patterns, we used several features of texture analysis obtained from Fourier power spectrum, gray-level histogram, difference statistics, co-occurrence matrix, and run length matrix.View full abstractDownload PDF (465K) -
Yongbum LEE, Du-Yih TSAI, Takao SUZUKI2008 Volume 25 Issue 3 Pages 48-53
Published: July 01, 2008
Released on J-STAGE: October 03, 2008
JOURNAL FREE ACCESSPre-processing is important for digital medical images because it can contribute to the improvement of diagnostic accuracy with medical images and computer-aided diagnosis. In this paper, a novel sigmoid-type transfer curve for wavelet coefficient weighting adjustment was proposed to improve contrast of medical images. The proposed method was applied to chest radiographs, mammograms and chest CT images, and then its performance was quantitatively evaluated with contrast improvement ratio. As a result, contrasts of all applied images were obviously improved. Compared with the conventional exponential-type transfer curve, the proposed sigmoid-type transfer curve was more effective with a statistical significance(p<0.05).View full abstractDownload PDF (735K) -
Masaki TSURUMAKI, Yongbum LEE, Du-Yih TSAI, Masaru SEKIYA, Kiyoko KAZA ...2008 Volume 25 Issue 3 Pages 54-60
Published: July 01, 2008
Released on J-STAGE: October 03, 2008
JOURNAL FREE ACCESSManual determination of an oblique sagittal imaging plane with high accuracy in lumbar spine magnetic resonance imaging(MRI)needs time, experience and expertise. In this paper we present a simple and fast setting system for assisting MRI operators in their routine work to automatically and accurately determine oblique sagittal imaging plane in lumbar spine MRI. The algorithm of the presented method consists of three major steps:(1)extraction of torso region from coronal localizer image by use of histogram analysis,(2)extraction of lumbar vertebra and spinal canal regions by use of minimization and maximization filters as well as density accumulation analysis, and(3)determination of the desired position and angle of sagittal imaging plane using Hough transform. In order to evaluate the performance of our proposed method, positions and angles of the sagittal imaging planes determined by the presented method were evaluated by five radiological technologists. Thirty healthy volunteers participated in this study. All the 5 observers confirmed that the automatically determined imaging planes of all the 30 cases were acceptable for subsequent imaging procedures.View full abstractDownload PDF (889K) -
Akira INOUE, Yasuhiko OKURA, Ikuo KAWASHITA, Katsuyoshi ITO, Naofumi M ...2008 Volume 25 Issue 3 Pages 61-69
Published: July 01, 2008
Released on J-STAGE: October 03, 2008
JOURNAL FREE ACCESSRecently, imaging techniques such as high magnetic field imaging and multidetector-row CT provides remarkable improvement in diagnosis. However, the latest imaging systems easily produce more than a thousand diagnostic images per patient. Image reading of a huge number of multi-modality images by use of a multi-formatted display and/or stack display method would be a hard work for radiologists. Therefore, we have developed a pixel-based comprehensive image processing method for the differential diagnosis of liver diseases by using multi-modality images. In this scheme, the criteria of an attendant radiologist for differential diagnosis for normal liver, cyst, hemangioma, hepatocellular carcinoma, and metastatic cancer on magnetic resonance images with various sequences and computed tomography images with and without contrast enhancement are employed. Total of 40 cases which including 10 cysts, 10 hemangiomas, 10 hepatocellular carcinomas, and 10 metastatic cancers are used in this study. The liver diseases could be correctly detected in all cases. The comprehensive image processing technique could assist radiologists for the differential diagnosis of the liver diseases.View full abstractDownload PDF (1053K)
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